The attacker behind the Coldcard breach didn't waste time. In just 10 minutes, they managed to siphon about $30 million by zeroing in on the biggest wallets first. Chainalysis’ investigation revealed that three of the top ten wallets taken held more than 10 BTC each, roughly $636,000 apiece at the time.
One victim alone lost $1.8 million during the initial wave. The attacker moved methodically, suggesting they surveyed the wallet ecosystem before launching their assault. This wasn’t random theft it was a calculated sweep designed to grab the highest-value targets before alarms could go off.
Within 25 minutes, around 500 wallets were drained, starting with the largest balances and quickly moving down to smaller ones. Chainalysis used its Reactor tool to trace the flow of stolen funds and pinpoint where the biggest hits occurred. The data showed a clear pattern: the attacker prioritized wallets with the heftiest bitcoin holdings to maximize the take before defenses kicked in.
Such a targeted approach means that even after applying software patches, wallets with vulnerable seeds remain at risk, highlighting the need for users to replace compromised seeds outright. This breach serves as a stark example of how hardware wallets, often considered the safest, can still be exploited if firmware weaknesses exist.
The Coldcard incident echoes wider concerns about hardware wallet security and the evolving tactics of attackers. Meanwhile, firms like Block continue probing how the attacker leveraged paid blockchain services during the sweeping attack, aiming to piece together the full story behind the massive $38 million-plus theft.
This content is for informational purposes only and does not constitute financial advice.
